The invention relates to adjustable steering columns for vehicles, and more particularly to a steering column with mechanism which enables both tilt adjustment and telescoping length adjustment.
Numerous types of adjustable steering mechanisms have been suggested and used previously. There have been many that have provided for both tilt adjustment and telescoping adjustment; others have encompassed tilt alone, or telescoping alone.
Examples of previous suggested systems providing both tilt and telescoping in a steering column are U.S. Pat. Nos. 1,367,695, 2,910,887, 3,267,766, 3,302,478 and 4,179,137. Steering columns which tilt but do not adjust in length are shown in U.S. Pat. Nos. 3,533,302, 3,555,924, 3,718,053 and 3,807,252, 4,217,792 and 4,244,237. The following patents show length adjustment, without tilt adjustment: U.S. Pat. Nos. 1,158,202, 2,075,110, 3,306,127, 3,791,223 and 3,955,439. One problem to which the present invention is directed is the provision of a tilt mechanism with a locking adjustment arrangement including a latch with engages in selected detents, but with the ability to achieve relatively fine adjustments in the tilt. Previously this was a problem, particularly when the tilt locking or latching mechanism was at a relatively low position on the steering column. In this situation, a relatively small tilt adjustment at the steering wheel is necessarily accompanied by an even smaller movement at the latching mechanism, and if detents are very closely spaced to allow for this, there tends not to be enough material left between the detents to provide adequate strength in the latching mechanism.
One patent directed to this problem was Glover et al. U.S. Pat. No. 3,267,766, cited above. The solution suggested by the Glover et al. patent was a series of movable, shiftable rollers to provide the detents. A latch was to engage between adjacent rollers, spreading them somewhat to form a detent. When the position of the latch was moved, increments of one roller thickness were available as closely spaced detent positions, thereby providing one movable detent with no fixed structure to separate detents.
The present invention described below is directed to a different, and more rigid latching assembly, without the requirement of close spacing of the detents.
Hansen U.S. Pat. No. 3,533,302, also cited above, shows a tilt steering assembly having some similarities to the mechanism of the present invention. However, Hansen does not show the latching mechanism of the present invention, nor the advantageous slide and guiding hardware for movement of the tilt latch system which forms a part of the present invention.